The long term objectives of the research proposal are to obtain detailed information about the functional properties of 3 lens fiber gap junctional proteins and the relationship between connexin structure and function. Detailed knowledge about these processes is important if we are to understand how the functional properties of different connexins contribute to organ homeostasis and how cataracts arise. There are 5 specific aims: 1. To characterize further the functional properties of 3 lens gap junctional proteins expressed in Xenopus oocyte pairs. 2. To characterize the behavior of single, nonjunctional cx46-induced channels in solitary oocytes. 3. To determine the role of the carboxyl terminal domain of cx46 and cx50 in channel function. 4. To determine the role of other protein domains in channel gating and permeation. 5. To characterize the functional properties of rat cx46 and rat cx50 in connexin-transfected mammalian cell lines using the dual patch clamp technique.